Furnace-grate.



PATENTED DBC. 18, 1906.

D. J. MGKENZIE. PURNAGE GRATE. APPLIOATIQN FILED APB. 13,1904.

4 SHEETS-SHEET 2.

PATENTBD DEG. 1s, 1906.

D. J. MOKENZIE. FURNAGB GRATE.

APPLIOATION Hmm APB.13,1904.

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No. 838,639. .PATENTED DEG. 18, 1906. D. J. MOKENZIE.

FURNAG'B GRATE. APPLICATION FLLED APR.13,1`9`04.

THE Nomus PE1-sas cn.. WASHING-ran, n. c.

DOUGAL J. MCKENZIE, CHICAGO, ILLINOIS.

FURNACE-GRATE.

Specification of Letters Patent.

Patented Dec. 18, 1906.

Application filed April 13,1904.. Serial No. 202,961.

.To mi] 'mi2/mn, it 'may concern."

Be it known that I, DOUGAL J. McInNZrn, a citizen of the United States, residing at Chicago, in the county of Cook and Stateof Illinois, have invented certain new and useful Improvements in Furnace Grates, of which the following is a specification.

The invention relates particularly to traveling grates as used in connection with boilerfurnaces, and especially to the construction and arrangement thereof by which the mass of burning fuel may be broken up and redistributed during the process of combustion, as will more fully hereinafter appear.

The principal object of the invention is to provide a simple, economical, and eflicient traveling grate of such construction and arrangement that it will automatically break up the mass of burning fuel during the process of combustion, so as to more thoroughly consume the same and obtain the greatest possible efficiency therefrom.

Other and further objects of the invention will appear from an examination of the drawings and the following description and claims.

The invention consists principally in a traveling grate for furnaces composed of at least two portions arranged on different planes and means for operating said portions I so as to automatically discharge the partiallyconsumed coal from one portion onto the other.

The invention consists, further and finally, in the features, combinations, and details of construction hereinafter described and claimed.

In the accompanying drawings, Figure l is a side elevation, partly in section, of a boiler and furnace as it appears when fitted with a traveling grate constructed in accordance with these improvements, Fig. 2, a front elevation showing the grate in section, Fig. 3, an enlarged sectional elevation taken on line 3 of Fig. 2 looking in the direction of the arrow, and Fig. 4, a skeleton plan view of a part of the supporting-frame mechanism with the shaft and gear mechanism by which the endless portions of the grate are supported and moved.

In the art to which this invention relates it is well known that during the process of burning inferior grades of coal on traveling grates the coal will run when the temperature reaches a certain high point. This is not only objectionable, but sometimes disastrous to the chain-grate mechanisms, and unless conditions are changed so that the coal may be consumed without any running7 the greatestj,efficiency of the fuel cannot be obtained, and, further, the grate mechanisms will quickly deteriorate. Again, during the combustion of high-grade coals on traveling grates made up of endless chains it is impossible to obtain the entire efficiency ofthe coal for the reason that after the first fiash of the gases during the process of combustion the coal becomes coked, and unless it be subsequently broken up the greatest possible efficiency thereof is not obtained. On the one hand, therefore, it will be seen that it is impracticable to obtain the full efficiency of low-grade coals, owing to their running and coking qualities, and that it is also impracticable to obtain the entire efficiency of highgrade coals, owing to their coking qualities, unless some means be provided for breaking up and distributing both of such classes of coals during the process of combustion. The principal object of this invention, therefore, is to provide a traveling grate of such construction and arrangement that the partiallyconsumed fuel will be broken up and redistributed during the process of combustion, thus insuring the greatest possible efficiency of the fuel, either low or high grade, and the longevity of the mechanisms, all of which will more fully hereinafter appear.

In illustrating and describing these vimprovements I have only illustrated and will here describe in connection with my new and novel elements so much of a furnace and boiler as are necessary to properly disclose the invention to others and enable those skilled in the art to practice the same, leaving out of consideration other and well-known elements which if set forth herein would only tend to confusion, proliXity, and ambiguity.

-In the drawings I have shown these improvements in connection with a tubular boiler af of the type which may be built up and supported in any of the usual ways incident to the use of such boiler. under the boiler and at the forward end thereof is the fire-box or furnace-chamber b, the forward end of which is provided with any of the different types of flat arches c.

To automatically feed the fuel into the furnace, and thus facilitate the combustion thereof, I provide a traveling-chain grate composed of front upper portions d and rear or inner lower portions e. The lower portions extend beyond the rear end of the upper IOO Immediately iro grate portions and away from such upper grate portions in the direction of the travel or movement of the upper laps of both` To support and move these grate portions in their desired paths, a single frame portionf is preferably provided and of the desired size, shape, and strength to contain and hold the operating and other parts in position. This frame is composed of two side portions tied together by means of a plurality of crossbeams g at different points throughout the length thereof. The front and rear portions of the grate as a whole are both divided in to a plurality of sections or subsections upon a line parallel with the path of movement of the grate, and each front upper portion of the grate, with the rear portion immediately back of it, can be operated together ata different speed from other parts of the grate. The grate as a whole may therefore be said to comprise a plurality of sections arranged parallel to each other, or separated upon a line parallel with the path of movement of the grate, each of such sections being separately movable and having a front upper and rear lower portion or subsection. These separately-movable or parallel-arranged sections being identical in all substantial respects a description of one section or any element thereof applies to the other section or as many of such sections or elements as it may be found desirable to employ. Shafts h and t' are rotatably mounted in the frame of the machine and provided with sprocket-wheels 7c, on and by which both front upper portions of the traveling grate are supported and moved, while shafts l and m are provided, each having a pair of sprocket-wheels a, on and by which the endless-ch ain grate mechanisms which compose the rear lower endless portions of the traveling grate are supported and moved.

To transmit power and motion to the grate mechanisms, each forward shaft 7L of the traveling grate is provided with a worm-wheel o, meshing with a worm p. A main drivingshaft q is provided and arranged transversely of the furnace in the hollow space of a boX- beam r, said main driving-shaft being connected with any desired prime mover and provided with a bevel-pinion s, meshing with a second bevel-pinion t on an intermediate shaft u. This intermediate shaft is provided with eccentrics v, connected with the lever mechanisms w on the worin-shaft, by means of the eccentric-straps and rods fr, the arrangement being such that when the main driving-shaft is rotated an intermittent stepby-step rotation is given to the worm-shaft and its worm p, which consequently transmits an intermittent motion to the forward portion of the traveling grate. It is also necessary to transmit power and motion to the rear portion of the endless grate, and while it is true that the endless chain which forms the `forward portion of the traveling grate would transmit some power an d motion from the shaft 7L to the shaft i it is not desirable to put all of the strain of power transmission thereon. Tn order to relieve it, therefore, the forward shafts h are each provided with bevel-pinions y, engaging with bevel-pinions z on longitudinally-arranged intermediate shafts 5. The rear ends of these intermediate shafts are also provided with bevel-pinions 6` engaging with bevelpinions 7 on the rear shaft i. By this arrangement it will be seen that the larger part of the transmission strain is taken off the chain mechanism of the traveling grate. This rear grate-shaft i is provided with aspurgear 8, connected with a spur-gear 9 on the shaft Z of the rear portion of the traveling grate by means of an intermediate spur-pinion 10, so that through the intermediary of this train of bevel and spur gears and pinions power and motion are transmitted to both portions of the traveling grate at the same time. The front and rear shafts h and m of the endless grate portions are adjustably and slidably mounted in the grate-frame by means of boxes 11, which are also adjustably held in position by means of the adjustingscrews 12. By this arrangement any desired tension may be placed upon both portions of the traveling grate to suit different circumstances and conditions.

To furnish a supply of fuel to the grate, the forward portion of the grate-frame is provided with a hopper portion 13, having an inclined bottom portion 14 and a verticallyarranged. slidable gate 15. This slidable gate is arranged to be moved up and down by means of rod mechanism 16, so that the space 17 between the lower portion of such grate and the upper portion of the grate-sur-` face may be regulated to permit the desired quantity of fuel to pass from the hopper into the combustion-chamber.

During the process of combustion and during the movement of the grate the coal or fuel which is on the forward upper portion of the grate will be partially consumed, and in the case of inferior coal it would be apt to run or coke, while in. the case of higher-grade coal when the first flash of the gases has taken place the remaining bed of the fuel would be apt to coke. It is highly desirable therefore in order to obtain all the efficiency of the coal possible as well as to save the mechanism from any deteriorating action, to break up and redistribute the mass of fuel. For this purpose the different portions of the grates are arranged at different levels, as hereinbefore described and as shown in the drawings. Tn order to assist in obtaining these results, an intermediate water-jacketed apron 18 is provided, as shown particularly in Figs. 1 and 3, with `its forward end arranged adjacent to the rear part of the for- IIO IIS

ward portion of the traveling grate. The fuel is brought into contact with the forward portion of this apron, is then broken up, partially delayed, and finally discharged over the upper portion of this apron down onto the lower portion of the grate. The mass of fuel is not only broken up by this means, but it is almost in all instances automatically turned upside down when it reaches the lower grate portion. The continued operations of the grate carry the mass of partiallyconsumed fuel to the rear portion of the furnace-chamber, and it will be understood that complete combustion or consumption should take place before it passes to the rear portion of the furnace. As the fuel, partiallyT or fully consumed, reaches the rear part of the furnace-chamber it contacts a second waterjacketed apron 19, arranged at the rear part thereof, where the fuel and solid products of combustion are then scraped off and forced over the same down onto the dumping-do or 20. This dumping-door is mounted upon an axle 21, one end of which is provided with a hand-wheel 22, by which such door may be dumped, so as to throw the ashes and other products into an ash-pit 28.

The grate-frame is provided, as shown particularly in Figs. l and 3, with rollers 24;, mounted upon tracks 25, which tracks may extend out in front of the furnace into the furnace-room, so that as occasion requires the entire grate can be withdrawn from the furnace for the purposes of renewal and repair and to meet different circumstances and conditions, all of which will be understood and appreciated by those skilled in the art.

It will also be noted that the water-aprons on these machines are not only arranged for the purpose of facilitating the breaking up and discharge of material from one portion of the grate to the other, but that they also prevent any ashes or rubbish from falling inside of the machine previous to its being discharged into the ash-pit, thereby preserving the fuel for as long a period as possible and insuring the longevity of the mechanisms.

As shown in Fig. 2, the endless grate is divided longitudinally. In other words, the shafts and grate portions are so divided that they become, in effect, parallel-arranged double-grate sections. It will also be noted that in this type of furnaces unusually wide fire-boxes can be used-as wide as twentyfive feet. In such event it will be almost impossible to keep the fire at the same point of temperature at each side of the grate, the consequence being that the user would at times be confronted with a condition in which coal on one side of the grate would be entirely consumed and on the other side only partially consumed, thus entailing great waste. It becomes desirable, therefore, to obviate such an objectionable condition, and

for this purpose the grate-supporting shafts 72 i, l, and m are divided and their central points supported in brackets 26, 27, 28, and 29, as shown, so that each parallel-arranged section comprising an upper forward and rear lower portion may be operated at a different speed from the other section or sec-- tions, as desired The grates upon the shafts are also divided longitudinally, as stated, and each forward shaft is provided with a separate worm-gear 0 and separate actuated eccentric and lever mechanisms for operating the same, while the centrally-arranged supporting-shafts l and i are also provided at their .outer ends with power-transmitting gears and-pinions 8, 9, and 10. It will also be seen that the connecting-point of the eccentric levers may be adjusted in the slot 30 of the worm-shaft lever by means of the hand-wheels 3l, and when it is desired to run one part of the parallel-arranged grate-sections faster or slower than the other that such adjustment movements may be quickly and readily accomplished, all of which will be understood and appreciated by those skilled in the art.

1. In a mechanism of the class described, the combination of a traveling grate, a plurality of endless portions thereof arranged to travel in different planes so that partiallyconsumed coal may be discharged from the upper to the lower portion, an apron placed intermediate the two grate portions to convey the partially-consumed coal from 'the upper to the lower grate portions, one end of said apron resting upon the upper grate portion to receive and break up the coal, and means for operating said grate portions at the same or different rates of speed.

2. In a mechanism of the class described, the combination with a supporting-frame of a plurality of supporting-shafts rotatively mounted between the side walls of said frame, a plurality of endless-chain grates supported by said shafts, the horizontal surfaces of said grates being on different levels, means to carry the fuel from the upper to the' lower grate, and an apron intermediate the two grates for turning the fuel over and breaking it up whereby complete combustion will be accomplished on the lower grate.

3. In mechanisms of the class described, the combination of a supporting-frame, a traveling grate formed of endless-chain portions arranged at a high level and rear endless-chain portions arranged at a lower level, supporting-shafts rotatably mounted in the frame of the machine and provided with sprocket-wheels for supporting and moving` the forward endless portions, a second pair of supporting-shafts rotatably mounted in the frame of the machine and provided with sprocket-wheels' for moving the rear lower endless portions, bevel-gear and pinion mech- IOO IIO

anism for transmitting power and motion from the forward supporting to the rear supporting shaft mechanism of the upper forward grate portions, and spur-gear mechanism for transmitting power and motion from the rear supporting-shaft mechanism of the forward grate portions to the forward supporting-shaft mechanism of the lower grate portions, substantially as described.

4. In mechanisms of the class described, the combination of a supporting-frame, a traveling grate formed of forward endlesschain portions arranged at a high level and rear endless-chain portions arranged at a lower level, supporting-shaft mechanism rotatably mounted in the frame of the machine and provided with sprocket-wheels for supporting and moving the forward endless portions, supporting-shafts rotatably mounted in, the frame of the machine and provided with sprocket-wheels for moving the rear lower endless portions, bevel-gear and pinion mechanism for transmitting power and motion from the forward supporting to the rear supporting shaft mechanism of the upper forward grate portions, spur-gear mechanism for transmitting power and motion from the rear supporting-shaft mechanism of the forward grate portions to the forward supporting-shaft of the lower grate portions, an intermediate discharging-apron to assist in breaking up and discharging the partiallyconsumed fuel from the forward upper to the rear lower portions of the grate, and a second or rear apron for breaking up and discharging the consumed fuel on the lower grate portions during the operation of the parts, substantially as described.

5. In mechanisms of the class described,

the combination of a supporting-frame, ay

traveling grate comprising a forward endlesschain grate portion arranged at a high level and a rear endless-chain grate portion arranged at a lower level, a pair of supportingshafts rotatably mounted in the frame of the machine and provided with sprocket-wlieels for supporting and moving the forward endless portion, a second pair of supportingshafts rotatably mounted in the frame of the machine and provided with sprocket-wheels for moving the rear lower endless portion, bevel-gear and pinion mechanism for transmitting power and motion from the forward supporting to the rear supporting shaft of the forward grate portion, spur-gear mechanism for transmitting power and motion from the shaft mechanism of the forward grate portion to the shaft mechanism of the lower grate portion, an intermediate dischargingapron for breaking up and discharging the partially-consuined fuel from the forward upper to the rear lower portion of the grate, a rear apron for breaking up and discharging the consumed fuel on the lower grate portion during the operation of the parts, wormgear mechanism on the shaft mechanism of the forward grate portion, a worm in engagement therewith, and eccentric and lever mechanism for imparting a step-by-step motion to such worin and connected mech anism so as to operate the parts of the grate, substantiallyT as described.

6. In mechanisms of the class described, the combination of a single supporting-frame, a traveling grate arranged thereon formed of a plurality of parallel sections each divided at right angles to its line of movement into a plurality of endless-chain grate portions, shaft mechanism. by which each of the endless portions of said traveling grate is supported and moved, and means for giving said shaft mechanism and thereby the parallel-arranged grate-sections the same or different rates of motion.

DOUGAL J. MCKENZIE.

Witnesses 1 THOMAS F. SHERIDAN, HARRY IRWIN CROMER. 

